1. Field of the Invention
The present invention relates to a riding detection device for a seat of a motorcycle or the like, and more particularly, to a structural arrangement which is advantageous for improving the sensitivity of the riding detection device.
2. Description of the Background Art
In Japanese Examined Patent Publication 121711/1995, there is disclosed a structure which constitutes a seat of a motorcycle or the like using a seat bottom plate, a seat cushion mounted on the seat bottom plate and a seat skin which covers the seat cushion. In this structure, a pressure-sensitive riding detection sensor is mounted on a central portion of the seat bottom plate. A rider riding on the seat is detected by this riding detection sensor when the rider sits on the seat.
In the above-mentioned structure, the riding detection sensor is mounted on the seat bottom plate and the thick seat cushion is mounted on the riding detection sensor and hence, the seating weight of the rider is absorbed by the thick seat cushion. Accordingly, there is a possibility that the sensitivity of the riding detection sensor is lowered. Further, since the seat bottom plate is required to have high-rigidity, when the seat bottom plate is made of resin or the like, a large number of ribs are generally formed on the seat bottom plate so that it is difficult to ensure a planar portion on which the riding detection sensor is arranged.
However, when the riding detection sensor is arranged immediately below the seat skin, for example, for the purpose of simply enhancing the sensitivity, it provides a rugged feeling to the rider and hence, the original function of the seat to provides a comfortable feeling to the rider is spoiled. Further, the riding detection sensor is required to barely respond to a weight other than the seating weight of the rider, such as the weight of luggage. Still further, the riding detection sensor is required to surely respond to the seating weight of the rider irrespective of a difference in the physical structure of the rider. The present invention aims at the realization of these demands.
To solve the above-mentioned problems, a riding detection device for a seat according to the present invention has a seat for a vehicle which includes a seat bottom plate, a seat cushion mounted on the seat bottom plate, and a seat skin covering a surface of the seat cushion, wherein a riding detection sensor is arranged at an intermediate portion in a vertical direction of the seat cushion.
Here, sensor supporting protrusions are formed on a portion of the seat cushion for supporting the riding detection sensor, and the riding detection sensor is supported on the sensor supporting protrusions. Further, the riding detection sensor is arranged so as to be extended in the forward and rearward directions at a central portion in the widthwise direction of the seat, and the riding detection sensor has a portion thereof disposed frontward from a hip point of a rider on the seat, elongated more. The upward and downward direction, the widthwise direction and the frontward and rearward direction of the seat cushion are determined by employing the use state of the seat as the reference.
The riding detection sensor according to the present invention is arranged at the intermediate portion in the vertical direction of the seat cushion and hence, the sensitivity to the seating weight of a rider can be enhanced and, at the same time, the feeling of the seat to the rider can be maintained in a favorable condition. Further, unlike the case of the seat bottom plate, it becomes easy to ensure a planar portion for arranging the riding detection sensor thereon so that the degree of freedom in the arrangement of the riding detection sensor can be increased.
Further, by providing the protrusions to a contact portion of the seat cushion where the seat cushion and the riding detection sensor come into contact with each other, the adjustment of the sensitivity is facilitated. Still further, by arranging the riding detection sensor such that the riding detection sensor is extended in the forward and rearward direction at a central portion in the widthwise direction of the seat and the riding detection sensor has the portion thereof disposed forwardly of the hip point of a rider, elongated more, even when there exists a difference in the physical structure of the rider, the seating portion is positioned above the riding detection sensor so that it becomes possible to make the sensitivity of the riding detection sensor barely respond to a weight other than the seating weight of the rider whereby the reliability of the riding detection sensor can be enhanced.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.